package net.dotool.demo;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.nio.charset.Charset;
import java.util.Iterator;

public class RobotServer {
	// 本地字符集
	private static final String LocalCharSetName = "UTF-8";

	// 本地服务器监听的端口
	private static final int Listenning_Port = 8888;

	// 缓冲区大小
	private static final int Buffer_Size = 1024;

	// 超时时间,单位毫秒
	private static final int TimeOut = 3000;

	public static void main(String[] args) throws IOException {
		// 创建一个在本地端口进行监听的服务Socket信道.并设置为非阻塞方式
		ServerSocketChannel serverChannel = ServerSocketChannel.open();

		serverChannel.socket().bind(new InetSocketAddress(Listenning_Port));
		serverChannel.configureBlocking(false);

		// 创建一个选择器并将serverChannel注册到它上面
		Selector selector = Selector.open();
		SelectionKey kk = serverChannel.register(selector, SelectionKey.OP_ACCEPT);
		kk.attach(new Runnable() {
			public void run() {
				System.out.println("---");
			}
		});

		while (true) {
			// 等待某个信道就绪
			if (selector.select(TimeOut) == 0) {
				continue;
			}

			// 获得就绪信道的键迭代器
			Iterator<SelectionKey> keyIter = selector.selectedKeys().iterator();
			// 使用迭代器进行遍历就绪信道
			while (keyIter.hasNext()) {
				SelectionKey key = keyIter.next();

				Object obj = key.attachment();
				if (obj != null && obj instanceof Runnable) {
					((Runnable) obj).run();
				}

				// 这种情况是有客户端连接过来,准备一个clientChannel与之通信
				if (key.isAcceptable()) {
					SocketChannel clientChannel = ((ServerSocketChannel) key.channel()).accept();
					clientChannel.configureBlocking(false);
					clientChannel.register(selector, SelectionKey.OP_READ, ByteBuffer.allocate(Buffer_Size));
				} else if (key.isConnectable()) {
					System.out.println("=========");
				} else if (key.isReadable()) {// 客户端有写入时
					// 获得与客户端通信的信道
					SocketChannel clientChannel = (SocketChannel) key.channel();
					// 得到并重置缓冲区的主要索引值
					ByteBuffer buffer = (ByteBuffer) key.attachment();
					buffer.clear();
					// 读取信息获得读取的字节数
					long bytesRead = clientChannel.read(buffer);
					if (bytesRead == -1) {
						// 没有读取到内容的情况
						clientChannel.close();
					} else {
						// 将缓冲区准备为数据传出状态
						buffer.flip();
						// 将获得字节字符串(使用Charset进行解码)
						String receivedString = Charset.forName(LocalCharSetName).newDecoder().decode(buffer)
								.toString();
						// 控制台打印出来
						System.out.println(receivedString);
						// 准备发送的文本
						String sendString = receivedString;
						// 将要发送的字符串编码(使用Charset进行编码)后再进行包装
						buffer = ByteBuffer.wrap(sendString.getBytes(LocalCharSetName));
						// 发送回去
						clientChannel.write(buffer);
						// 设置为下一次读取或是写入做准备
						key.interestOps(SelectionKey.OP_READ | SelectionKey.OP_WRITE);
					}
				}

				keyIter.remove();
			}
		}

	}
}